Fluid transport systems typically comprise multiple consumers, meaning parallel branches or lines, through which a liquid or gaseous fluid is transported—for example to distribute thermal energy. The consumers typically have different designs, meaning that they have different diameters and/or lengths of the transport lines—for example, pipe conduits—and have different and/or varying flow volumes and/or throughput. In order to undertake a balanced and/or compensated distribution of the fluids to the consumers in such fluid transport systems, the consumers are each configured with a compensation- or balancing organ, for example an adjustable actuator, particularly a valve, which can set the flow through the respective consumer at different degrees of opening and/or valve positions.
A balancing method for a network for the distribution of a non-compressed liquid is described in DE 69706458, wherein for each branch, two pressure connection points are arranged on both sides of the compensating organ, and a further third pressure connection point is arranged at a distance therefrom. In all branches, flow measurements are carried out by measuring the difference in flow on both sides of the respective compensating organ, and a measurement of a pressure difference is carried out by means of the third pressure connection point. On the basis of these measured values, the hydraulic flow capacity coefficients of all branches and segments on the primary line are calculated. Finally, the adjustment positions of each compensating organ are calculated and set on the basis of knowledge of the desired flow in each branch and utilizing the specific flow capacity coefficients. The compensation method requires multiple pressure connection points for each compensating organ, and is not designed for a dynamic balancing of a fluid transport system.
EP 2 085 707 shows the hydraulic balancing of a heating system, wherein a heating element is equipped with a measuring device for measurement of the pressure and flow volume. Means are included for the detection of the flow volume as provided, as are means for detecting the pressure difference between the in-flow and the outlet flow. Means for the detection of the flow volume are arranged on the heating element, and serve the purpose of eliminating errors and automating the balancing. EP 0 795 724, which is in the same patent family as DE 69706458, shows substantially the same features as DE 69706458.
DE 199 12 588 shows a hydraulic system having multiple conduit lines. For the purpose of improving the regulating behavior, valves with an electronic flow volume measuring device and an actuator drive are arranged in both a primary circuit and in the conduit lines of the consumer circuits.
EP 2 157 376 shows an arrangement for hydraulically balancing a system for the purpose of cooling or heating. The system has an in-flow line, an outlet flow line, a throttle device, and a measuring device for a flow volume. Valves are included in each line for the purpose of hydraulic balancing, and measuring means are included for the purpose of determining the flows into the individual lines.
U.S. Pat. No. 8,024,161 describes a method and system for optimal model-based multivariable balancing for distributed hydraulic networks based on global differential pressure/flow rate information. U.S. Pat. No. 8,024,161 uses a simplified mathematical model of a hydraulic network and a set of measured flow values in all the zones of the hydraulic network to identify unknown network parameters. According to U.S. Pat. No. 8,024,161, valve settings are balanced by calculating the sum of pressure drops across the balancing valves and by solving an optimization problem to minimize the sum of pressure drops across the balancing valves in a non-iterative approach.
Therefore, in these prior art systems, a separate sensor is included in each consumer for the purpose of determining the flow. As a result, a great degree of complexity is particularly inherent in the installation process.